* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  img {
    /* 去除掉图片默认的3px */
    display: block;
    width: 100%;
  }
  a {
    text-decoration: none;
    /* 让a标签的字体颜色 继承 */
    color: inherit;
  }
  ul {
    list-style: none;
  }
  input {
    border: none;
    outline: none;
  }
  .clearfix::after {
    content: "";
    display: block;
    height: 0;
    line-height: 0;
    visibility: hidden;
    clear: both;
  }
  